SN4 ""

No	Pattern	Freq
1	be [adj] [to-vb] [Wh adv] the [noun sg]	106
2	be [adj] [to-vb] how the [noun]	86
3	is [adj] [to-vb] [Wh adv] the [noun]	81
4	be [adj] to see [Wh adv] the [noun]	62
5	be difficult [to-vb] [Wh adv] the [noun]	32
6	be [adj] [to-vb] why the [noun]	26
7	be [adj] [to-vb] [Wh adv] the [noun pl]	25
8	be easy [to-vb] [Wh adv] the [noun]	23
9	be [adj] [to-vb] [Wh adv] the [noun]	22
10	be [adj] [to-vb] where the [noun]	21
11	was [adj] [to-vb] [Wh adv] the [noun]	16
12	be [adj] to understand [Wh adv] the [noun]	15
13	be hard [to-vb] [Wh adv] the [noun]	14
14	be [adj] to know [Wh adv] the [noun]	10
15	be interesting [to-vb] [Wh adv] the [noun]	10
16	be able [to-vb] [Wh adv] the [noun]	9
17	's [adj] [to-vb] [Wh adv] the [noun]	9
18	be [adj] [to-vb] [Wh adv] the [noun prp]	8
19	be necessary [to-vb] [Wh adv] the [noun]	7
20	be [adj] to explain [Wh adv] the [noun]	7
21	be impossible [to-vb] [Wh adv] the [noun]	7
22	be important [to-vb] [Wh adv] the [noun]	6
23	be unable [to-vb] [Wh adv] the [noun]	5
24	be [adj] to tell [Wh adv] the [noun]	5